Process of fumigating and disinfecting



sam Oct. 28,1924.

UNlTEDSTA-TES PATENT or FlCE.

WALTER S. LANDIS, OF WHITESTONE LANDING, NEW YORK, AND GUY-H. BUCHANAN, 0F WESTFEIED, NEW JERSEY, TO AMERICAN CYANAMID COMPANY, OF NEW 103K, N. Y., A GOBZQPORATION OF MAINE.

' PROCESS OF FUMIGATIHG AND DISINFEG'I 'ING.

3310 Drawing.

To all whom it may concern:

Be it known that we,WALrEB .0. LANDIS and Guy H. BtIcHANAiv, citizens of the United States, respectively residing at Whitestone Landing, in the count of Queens, State of New York, and West eld, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Processes of Fumigating and Disinfecting; and we do hereby declare the following to be a full,clear, and exact description of the invention, such as will enable others skilled inthe art to which-it appertains'to make and use the same.

This invention relates to a method of simultaneously fumigating and disinfecting enclosed spaces, and has for its object'to provide a process of this nature which will be comparatively simple and inexpensive to carry out, as well as more eflicient than those which have been heretofore proposed.

With these and other. objects in view, the invention c'onsists in the novel steps and combinations of steps constituting the method,

all as will be more fully hereinafter disclosed and particularly pointed out in the claims.

In order thatthe precise nature of the invention may be the more clearly understood,

it is said In comparatively recent years, hydro cyanic acid gas has come to be used very extensively as a fumigant for the purpose'of eliminating vermin from buildings, ships, vegetation, and other infested places. Its disinfecting or deodori'zing value, however,

seems to be rather less than its fumigation value, and it would, therefore, be of decided advantage to be able to usewith it a;satis factory deodorizer' or disinfectant, and so perform both operations at once.

In our copending application, filed July 8, 1921, Serial N 0'. 483,262, entitled Process of fumigating, we have disclosed the use of various aldehydes and accelerating agents for destroying hydrocyanic acid after fumi gation. Now one of the more common aldehydes is formaldehyde, which is a good disinfectant or deodorizer, but of no substantial value as an insecticide as compared with hydrocyanic acid. We have shown in our said copendingapplication that the reaction between hydrocyanic acid and the various volatile aldehydes is extremely-slow without an eccelerating agent and in this invention Application filed my 8,-

1921. Serial No. 483,283.

' we propose to introduce hydrocyanie acid gas and formaldehyde into the-enclosed space at the-same time, to the end that fumigation and disinfection may be carried on simultaneously.

The concentration of hydrocyanic acid usually employed for fumigation purposes ranges from 0.2 of one per cent to one per cent ormore, by volume, and the dosage of formaldehyde gas which we find most,'suitable for effective use is f om one to two ounces of gas, (EH 0, per- 1000 cubic feet of space.-

When this quantity is introduced into a space .suitably charged with hydrocyanic acid for effective fumigation, ractically no reaction takes'place between t e two gases for four or five hours, orfor a time more than suflicient for either fumigation or disinfection to be accomplished. In fact, no appreciable decomposition of' either gas takes place until the proportion of formaldehyde'gas is up wards ofthree'or four times that needed for disinfection. Where the proportion of formaldehyde exceeds about five times the disinfecting standard,--or from say,5 to 10 ounces perlOOO cubic feet of space, then do composition begins to show up in about five hours, to the extent of a 'lossof about onethird of the hydrocyanic acid present, As hydrocyanic acid is usually effective as a fumigant, when propenly applied, in about two hours or less, this decomposition is not serious; Naturally these relationships are altered when accelerating agents are used, as

disclosed in our said copending application above mentioned.

In carrying out our present process, the

hydrocyanic acid may be introduced in' the I usualmanner, as, for example, by spraying or atomizing liquid acid into the enclosure, or

by direct generation'therein from a reaction between sulphuriccacid and sodium cyanide The. formaldehyde is then introduced in any desired manner, as by atomizing a formalin solution, or preferabl by the chemical methods of generation. At the end of*the operation and after the necessary time has elapsed, the room 'orfiother space may be opened up orventila-ted, orinore formaldehyde withan accelerating agent may be introduced and the hydrocyaniq acid .destroyed, as disclosed in oursaid copending appliedtion, Serial No. 483,262, filed Ju1y 8, 1921, for process of fumigating.

It is obvious that those skilled in the art may vary the exact details of procedure without departing from the spirit of the invention, and therefore we do not wish to be limited to the above disclosure except as may i be required by the claims.

What we claim is: I 1. The process of simultaneously fumigating and disinfecting an enclosed space which consists in' introducing hydrooyanic acid gas into said space, together with a disinfectant comprising a volatile aldehyde said fumigation and disinfection, substaxi tially as described.

2. The process of simultaneously fumigating and disinfecting an enclosed space which consists in introducing hydrocyanic acid gas'and formaldehyde intosaid space, under such conditions that substantially no chemical reaction takes place between them for a period of time reater thantwo hours; and maintaining said materials within said space for a time sufiicient to accomplish fumigation and disinfection, substantially as described.

tures.

WALTER s. 'LANDIS. GUY H. BUCHANAN.

In testimony whereof we afiix our signa- 

